A structure that has a three-dimensional network structure formed by a substance having the ability to form a gel (hereinafter called a gelator) and contains a fluid in the network structure is called a gel. In general, a gel containing water as the fluid is called a hydrogel, and another gel containing an organic liquid (such as organic solvents and oils) except water is called an organogel or an oil gel. The oil gel (organogel) is used in the fields of cosmetics, pharmaceutical products, agrochemicals, foods, adhesives, paints, resins, and other products to control the flowabilities of cosmetics and paints. The oil gel (organogel) is also widely used in the field of environmental preservation, for example, to form a gel as a solid from oil waste, thus preventing water pollution.
Gelators have been studied mainly on polymer compounds, but in recent years, low-molecular weight compounds, to which various functions can be easily introduced as compared with the polymer compounds, have been being studied. As described above, the oil gels (organogels) have been used in a wide variety of fields and are expected to be used in wider fields in future. On this account, as the application fields of the oil gels expand, gelators of low-molecular weight compounds (hereinafter also called low-molecular weight gelators) are required to have ability to form a gel from a wide variety of organic solvents. To address these requirements, a urea compound has been disclosed as a low-molecular weight gelator capable of forming a gel having excellent stability from various organic solvents by adding a small amount of the compound (for example, Patent Documents 1 and 2). It is also disclosed that an α-aminolactam derivative has the ability to form gels from squalane, a liquid paraffin, and other substances (for example, Patent Document 3).
Sugar derivatives derived from various monosaccharides have a structure readily forming strong hydrogen bonds to each other, and it has been disclosed that the sugar derivatives form gels from various organic solvents (Non-Patent Document 1).